1. Field of the Invention:
This invention relates to the packaging art and has particular reference to an improved container for packaging a fragile article such as an electric bulb, and to an improved lamp package which utilizes such a container.
2. Description of the Prior Art
As is well known in the lamp industry, incandescent and other types of lamp bulbs are protected during shipment by inserting the bulb into a wrapper or container of stiff paperboard that is open at both ends and can be collapsed for bulk shipment from the container manufacturer to the lamp factory. Such containers are of tubular configuration and have four walls that make a snug frictional fit with the inserted lamp bulb. In order to prevent the bulb from slipping out of the container and breaking while the lamp package is being handled in the factory or store, it was essential that the interior dimensions of the container be precisely controlled in order to effect the required tight frictional fit with the inserted lamp bulb. Even when the proper fit was obtained, the lamp bulb would still frequently slip out of the container and break, especially if the container was bent out of shape or damaged. It has also been found that the lamp, in transit, will vibrate and cause the fluting to collapse in the maximum diameter area of the bulb. This enlarges the inside dimension of the wrapper and causes the bulb to slip out at the point of sale.
Due to the inherent stiffness of the sheet material from which the sleeve or container is fabricated, such containers also have a natural tendency to return to their collapsed condition even after they have been erected into tubular form and loaded with a lamp bulb. This not only reduced the frictional grip of the container on the inserted bulb but destroyed the "squared-up" configuration of the lamp packages which prevented them from being stacked properly on the store shelves.
A single-lamp open-ended container having a pair of parallel interior panels with openings and hinged tab portions that retain the lamp bulb in its inserted position and lock the sleeve in tubular configuration is disclosed in U.S. Pat. Nos. 3,547,256 and 3,820,707.
Cartons with closure flaps at each end and a hinged internal panel that forms a spaced liner or cell structure which locks the inserted article in position with the carton and spaces it from the carton walls are disclosed in U.S. Pat. Nos. 2,893,623 - 2,764,337 - 2,732,996 - 2,714,981 and 2,611,529.
An open-ended container of corrugated paper having an inwardly-protruding planar tab or brace with a curved edge that interlockingly engages an inserted lamp bulb and retains it in place is disclosed in U.S. Pat. No. 3,162,303.